* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Arial', sans-serif;
    line-height: 1.6;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
}

.navbar {
    background: rgba(255, 255, 255, 0.95);
    padding: 1rem 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
    position: sticky;
    top: 0;
    z-index: 1000;
}

.logo {
    font-size: 1.8rem;
    font-weight: bold;
    color: #667eea;
}

.nav-links {
    display: flex;
    list-style: none;
    gap: 1.5rem;
}

.nav-links a {
    text-decoration: none;
    color: #333;
    font-weight: 500;
    transition: color 0.3s;
    padding: 0.5rem 1rem;
    border-radius: 5px;
}

.nav-links a:hover,
.nav-links a.active {
    color: white;
    background: #667eea;
}

.hero {
    text-align: center;
    padding: 4rem 2rem;
    color: white;
}

.hero h1 {
    font-size: 3rem;
    margin-bottom: 1rem;
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.3);
}

.hero p {
    font-size: 1.3rem;
    margin-bottom: 2rem;
}

.btn-primary {
    display: inline-block;
    padding: 1rem 2.5rem;
    background: white;
    color: #667eea;
    text-decoration: none;
    border-radius: 50px;
    font-size: 1.1rem;
    font-weight: bold;
    transition: transform 0.3s, box-shadow 0.3s;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.2);
}

.btn-primary:hover {
    transform: translateY(-3px);
    box-shadow: 0 6px 20px rgba(0, 0, 0, 0.3);
}

.features {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    padding: 3rem 2rem;
    max-width: 1200px;
    margin: 0 auto;
}

.feature-card {
    background: white;
    padding: 2rem;
    border-radius: 15px;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
    text-align: center;
    transition: transform 0.3s;
}

.feature-card:hover {
    transform: translateY(-10px);
}

.feature-card h3 {
    color: #667eea;
    margin-bottom: 1rem;
    font-size: 1.5rem;
}

.feature-card p {
    color: #666;
}

footer {
    text-align: center;
    padding: 2rem;
    background: rgba(0, 0, 0, 0.2);
    color: white;
    margin-top: 3rem;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 2rem;
}

.quiz-container {
    background: white;
    padding: 3rem;
    border-radius: 15px;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.2);
    max-width: 800px;
    margin: 2rem auto;
}

.question {
    font-size: 1.5rem;
    margin-bottom: 2rem;
    color: #333;
}

.options {
    display: grid;
    gap: 1rem;
}

.option-btn {
    padding: 1rem 2rem;
    background: #f0f0f0;
    border: 2px solid #ddd;
    border-radius: 10px;
    cursor: pointer;
    transition: all 0.3s;
    font-size: 1.1rem;
    text-align: left;
}

.option-btn:hover {
    background: #667eea;
    color: white;
    border-color: #667eea;
}

.option-btn.correct {
    background: #4CAF50;
    color: white;
    border-color: #4CAF50;
}

.option-btn.incorrect {
    background: #f44336;
    color: white;
    border-color: #f44336;
}

.score-display {
    text-align: center;
    padding: 2rem;
    background: #f8f9fa;
    border-radius: 10px;
    margin-bottom: 2rem;
}

.score-display h2 {
    color: #667eea;
    font-size: 2rem;
}

.quiz-nav {
    display: flex;
    justify-content: space-between;
    margin-top: 2rem;
}

.btn-secondary {
    padding: 0.8rem 2rem;
    background: #6c757d;
    color: white;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    font-size: 1rem;
    transition: background 0.3s;
}

.btn-secondary:hover {
    background: #5a6268;
}

.btn-success {
    padding: 0.8rem 2rem;
    background: #28a745;
    color: white;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    font-size: 1rem;
    transition: background 0.3s;
}

.btn-success:hover {
    background: #218838;
}

.categories-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    padding: 2rem;
}

.category-card {
    background: white;
    padding: 2rem;
    border-radius: 15px;
    text-align: center;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
    transition: transform 0.3s;
    cursor: pointer;
    text-decoration: none;
    color: #333;
}

.category-card:hover {
    transform: scale(1.05);
}

.category-card h3 {
    color: #667eea;
    margin-bottom: 1rem;
    font-size: 1.5rem;
}

.category-card p {
    color: #666;
}

.table {
    width: 100%;
    background: white;
    border-radius: 10px;
    overflow: hidden;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
}

.table thead {
    background: #667eea;
    color: white;
}

.table th,
.table td {
    padding: 1rem;
    text-align: left;
}

.table tbody tr {
    border-bottom: 1px solid #eee;
}

.table tbody tr:hover {
    background: #f8f9fa;
}

.form-group {
    margin-bottom: 1.5rem;
}

.form-group label {
    display: block;
    margin-bottom: 0.5rem;
    color: #333;
    font-weight: 500;
}

.form-group input,
.form-group textarea,
.form-control {
    width: 100%;
    padding: 0.8rem;
    border: 2px solid #ddd;
    border-radius: 8px;
    font-size: 1rem;
}

.form-group input:focus,
.form-group textarea:focus {
    outline: none;
    border-color: #667eea;
}

@media (max-width: 768px) {
    .nav-links {
        flex-wrap: wrap;
        gap: 0.5rem;
    }
    
    .hero h1 {
        font-size: 2rem;
    }
    
    .features {
        grid-template-columns: 1fr;
    }
}